REVENUES - Schedule of Revenues Disaggregated by Major Products and Service Lines and Timing of Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Disaggregation of Revenue [Line Items]
Revenues	$ 411,643	$ 322,606	$ 771,131	$ 594,512
Revenues	411,643	322,606	771,131	594,512
Revenue from goods or services transferred to customers over time
Disaggregation of Revenue [Line Items]
Revenues	100,993	80,122	198,141	158,695
Revenue from goods or services transferred to customers at a point in time
Disaggregation of Revenue [Line Items]
Revenues	310,650	242,484	572,990	435,817
Off-platform
Disaggregation of Revenue [Line Items]
Revenues	192,618	131,176	345,482	227,526
GigaCloud 1P
Disaggregation of Revenue [Line Items]
Revenues	98,114	94,209	188,127	175,594
Others
Disaggregation of Revenue [Line Items]
Revenues	85	297	156	400
Product sales to B
Disaggregation of Revenue [Line Items]
Revenues	92,457	64,414	159,846	108,399
Product sales to C
Disaggregation of Revenue [Line Items]
Revenues	100,161	66,762	185,636	119,127
Platform commission
Disaggregation of Revenue [Line Items]
Revenues	6,245	4,806	11,750	9,141
Ocean transportation service
Disaggregation of Revenue [Line Items]
Revenues	10,679	8,312	18,528	19,670
Drayage service
Disaggregation of Revenue [Line Items]
Revenues	3,138	3,242	6,288	6,014
Warehousing service
Disaggregation of Revenue [Line Items]
Revenues	16,043	13,480	32,110	27,558
Packaging service
Disaggregation of Revenue [Line Items]
Revenues	9,282	8,267	18,808	15,517
Last-mile delivery service
Disaggregation of Revenue [Line Items]
Revenues	70,039	53,949	139,032	103,193
Others
Disaggregation of Revenue [Line Items]
Revenues	5,400	4,868	10,850	9,899
Service revenues
Disaggregation of Revenue [Line Items]
Revenues	120,826	96,924	237,366	190,992
Total product revenues
Disaggregation of Revenue [Line Items]
Revenues	$ 290,817	$ 225,682	$ 533,765	$ 403,520